Modern telecommunications networks provide telephone users with a myriad of advanced features in addition to performing their primary function of placing calls between users. Advanced features such as call waiting, caller identification, caller call back, and handling of calls from wireless users are now standard features offered by most telephone service providers. In order to offer such advanced features, the telecommunications networks of a service provider must be configured to support these features.
One type of modern telecommunications network is a Global System for Mobile Communications (GSM) network, where GSM is a digital cellular phone technology utilizing time division multiple access (TDMA) modulation to communicate signals over the network. The concepts and principles discussed herein apply to other types of telecommunications networks as well, such as Universal Mobile Telecommunications System (UMTS) networks. A GSM network is described herein merely by way of example. FIG. 1 is a functional block diagram of a conventional GSM network 100 including a mobile station 102 that is typically a cellular phone and which communicates over a wireless communications channel 104 with a base station subsystem 106. The base station subsystem 106 communicates with mobile stations 102 in the geographical region or “cell” covered by the system 100, and also communicates with a network subsystem 108 to route calls to and from the mobile stations 102 and verify registration and authenticate information of a subscriber using a mobile station.
The network subsystem 108 includes a mobile switching center (MSC) 110 that communicates with the base station subsystem 106 and also routes messages to and from other components in the network subsystem to verify subscriber registration and authentication information and to perform other functions such as location updating of mobile stations 102. The base station subsystem 106 typically communicates through transaction capabilities applications part (TCAP) messages, which are messages formed according to a specific protocol for communication in the network subsystem 108. The network subsystem 108 further includes signal transfer points (STPs) 112, 114 that route the TCAP messages to appropriate points in the network based upon routing information contained in each TCAP message. More specifically, a destination point code (DPC) and a signaling connection control point (SCCP) called party address dictate routing of the TCAP messages between components in the network 100, as will be understood by one skilled in the art. In this way, each STP 112, 114 functions as a network hub and thereby eliminates the need for direct links between components in the network 100. The network subsystem 108 also includes a pair of home location registers (HLRs) 116, 118, each HLR being a database that stores subscriber information such as registration, feature, and authentication data associated with each subscriber. The network subsystem 108 further includes a second MSC 120 in the example embodiment of FIG. 1 which functions in the same way as the MSC 110. Note that the network 100 can include one or more HLRs.
In operation, when a subscriber initiates a call from his or her mobile station 102, a corresponding message is communicated over the wireless communications channel 104 and through the base station subsystem 106 to the MSC 110. In response to this message, the MSC 110 communicates, via the STPs 112, 114, with the appropriate HLR 116, 118 to verify registration and authentication information for the first subscriber. Once this information has been verified, the MSC 110 routes a TCAP message to a second subscriber to thereby connect or place the call. The MSC 110 determines proper routing of this TCAP message from a dialed number contained in the initial message from the mobile station 102 which is communicated via the communications channel 104 and subsystem 106 to the MSC. The HLRs 116, 118 are the databases within the network subsystem 108 that store all subscriber information and operate in combination with the MSCs 110, 120 as threshold components in granting or denying mobile phone subscribers access to the network subsystem 108.
A number of wireless carriers or service providers typically utilize the network 100 to provide mobile telephone service to their respective subscribers. Each service provider must implement and maintain an HLR 116, 118 to provide service to their subscribers. In many situations, a wireless service provider hires a third party company to provide and maintain the HLR 116, 118 for the provider. The third party company initially establishes the HLR 116, 118 and thereafter maintains the HLR as subscribers are added and removed and the features of each subscriber are changed. Service providers may at some point wish to retain a new company to maintain the HLR 116, 118, and in this situation the subscriber entries in the current HLR must be transferred to a new HLR being established and maintained by the new company. Another situation in which the need to transfer subscriber entries from a first HLR 116, 118 to a second HLR arises when a service provider is expanding and wants to redistribute subscribers to a different HLR within the network subsystem 108.
Typically, to transfer an HLR 116, 118 from an old company to a new company, routing configuration information in the network subsystem 108 must be reconfigured to route calls directed to the old HLR to the new HLR. This approach is very labor intensive and thus timely and expensive to implement. Another approach is to simply transfer all subscriber entries from the old company's HLR 116, 118 to the new company's HLR. This approach is not always possible or practical given that HLRs 116, 118 may contain millions of subscriber entries and thus the delay and expense for transferring all these entries is not practical. Moreover, in this approach the new HLR 116, 118 may not be utilized until all subscriber entries have been transferred, delaying implementation of the new HLR. Thus, until the transfer of all subscriber service to the new HLR 116, 118 is completed the old HLR must be used, or, alternatively, service for the underlying subscribers must be suspended during completion of the subscriber service transfer to the new HLR.
There is a need for a system and method that allows a service provider to more easily transfer subscriber data from one HLR to another and which enables service to be maintained by a service provider during such transfers.